Alexis St. Martin, a Canadian voyageur, is accidentally shot with a musket at close range at the fur trading post on Mackinac Island on June 6, 1822.

The charge of the musket shot leaves a hole through his side that will heal to form a fistula aperture into his stomach.

William Beaumont, a U.S. Army surgeon stationed at a nearby army post, treats the wound.

Although St. Martin is a healthy twenty-year-old, he is not expected to recover due to the severity of his wound.

Beaumont will explain in a later paper that the shot had blown off fragments of St. Martin's muscles and had broken a few of his ribs.

After bleeding him and giving him a cathartic, Beaumont will mark St. Martin's progress.

For the next seventeen days, all food he eats will re-emerge from his new gastric fistula.

Finally, after seventeen days, the food will begin to stay in St. Martin's stomach and his bowels will begin to return to their natural functions.

When the wound heals itself, the edge of the hole in the stomach will have attached itself to the edge of the hole in the skin, creating a permanent gastric fistula.

There is very little scientific understanding of digestion at this time and Beaumont will recognize the opportunity he has in St. Martin—he will literally be able to watch the processes of digestion by dangling food on a string into St. Martin's stomach, then later pulling it out to observe to what extent it had been digested.

Beaumont will continue to experiment on St. Martin off and on until 1833.